639 research outputs found
Parity Violating Gravitational Coupling Of Electromagnetic Fields
A manifestly gauge invariant formulation of the coupling of the Maxwell
theory with an Einstein Cartan geometry is given, where the space time torsion
originates from a massless Kalb-Ramond field augmented by suitable U(1) Chern
Simons terms.We focus on the situation where the torsion violates parity, and
relate it to earlier proposals for gravitational parity violation.Comment: 7 Pages, Latex . no figures, Replaced with Revtex version, many
references added and typos correcte
Molecular dynamics studies on phenol– water clusters
Architectures of the molecules and their behavior in the clustered system are important for various consequence functions in the realistic environment. In order to gain detailed knowledge of the phenol-water clusters, 1-nano second (ns) the molecular dynamic (MD) simulation has been performed. The various structural parameters have been obtained from the MD trajectories. MD simulation reveals the presence of well-defined hydrogen-bonded network of water molecules around the phenol molecule and their dynamics. The existence of cooperativity in the hydrogen bonding and high dynamics nature of hydrogen-bonded network are evident from the present study. The calculated mutual diffusion coefficient is in close agreement with the experimental value of the phenol-water system
Design of low-cost ionic liquids for lignocellulosic biomass pretreatment
The cost of ionic liquids (ILs) is one of the main impediments to IL utilization in the cellulosic biorefinery, especially in the pretreatment step. In this study, a number of ionic liquids were synthesized with the goal of optimizing solvent cost and stability whilst demonstrating promising processing potential. To achieve this, inexpensive feedstocks such as sulfuric acid and simple amines were combined into a range of protic ionic liquids containing the hydrogen sulfate [HSO] anion. The performance of these ionic liquids was compared to a benchmark system containing the IL 1-ethyl-3-methylimidazolium acetate [CCim][OAc]. The highest saccharification yields were observed for the triethylammonium hydrogen sulfate IL, which was 75% as effective as the benchmark system. Techno-economic modeling revealed that this promising and yet to be optimized yield was achieved at a fraction of the processing cost. This study demonstrates that some ILs can compete with the cheapest pretreatment chemicals, such as ammonia, in terms of effectiveness and process cost, removing IL cost as a barrier to the economic viability of IL-based biorefineries
Parabolic bundles on algebraic surfaces I - the Donaldson-Uhlenbeck compactification
The aim of this paper is to construct the parabolic version of the Donaldson-Uhlenbeck compactification for the moduli space of parabolic stable bundles on an algebraic surface with parabolic structures along a divisor with normal crossing singularities. We prove the non-emptiness of the moduli space of parabolic stable bundles of rank 2
Quantum Aspects of Black Hole Entropy
This survey intends to cover recent approaches to black hole entropy which
attempt to go beyond the standard semiclassical perspective. Quantum
corrections to the semiclassical Bekenstein-Hawking area law for black hole
entropy, obtained within the quantum geometry framework, are treated in some
detail. Their ramification for the holographic entropy bound for bounded
stationary spacetimes is discussed. Four dimensional supersymmetric extremal
black holes in string-based N=2 supergravity are also discussed, albeit more
briefly.Comment: 13 Pages Revtex with 3 eps figures; based on plenary talk given at
the International Conference on Gravitation and Cosmology, Kharagpur, India,
January, 2000 One reference adde
INTERNATIONAL JOURNAL OF PHARMACY & LIFE SCIENCES A breakthrough in health care textiles -antiviral surgical gown
Abstract The surgical gowns were originally used to protect patients from post-surgery infection caused by contaminants in the environment. In the recent health care scenario, the function of surgical gowns has become bidirectional. They serve to minimize the cross-infection between patients and health care workers. The health care workers are mainly being exposed to various blood borne pathogens when performing surgeries or post surgeries. The surgical gowns are specifically used to protect the health care workers from being exposed to infectious agent's particularly bloodborne pathogens such as human immunodeficiency virus (HIV), hepatitis B and C virus, which could be acquired by contact between the contaminated body fluids and non-intact skin or mucous membranes. Health care workers in operating rooms, isolation areas, emergency rooms and intensive care units are in absolute and essential necessity of Protective clothing. As a part of personal protection, surgical gowns are used as protective equipment, widely in healthcare facilities. Surgical gowns can be constructed by either single-use materials or reusable materials. Each of these has their own advantages and disadvantages. Woven reusable surgical gowns can be made of tightly woven all-cotton muslin, blended sheeting, polyester sheeting and composite materials
Repetition Aware Text Indexing for Matching Patterns with Wildcards
We study the problem of indexing a text T[1..n] to support pattern matching with wildcards. The input of a query is a pattern P[1..m] containing h ∈ [0, k] wildcard (a.k.a. don't care) characters and the output is the set of occurrences of P in T (i.e., starting positions of substrings of T that matches P), where k = o(log n) is fixed at index construction. A classic solution by Cole et al. [STOC 2004] provides an index with space complexity O(n ⋅ (clog n)^k/k!)) and query time O(m+2^h log log n+occ), where c > 1 is a constant, and occ denotes the number of occurrences of P in T. We introduce a new data structure that significantly reduces space usage for highly repetitive texts while maintaining efficient query processing. Its space (in words) and query time are as follows:
O(δ log (n/δ)⋅ c^k (1+(log^k (δ log n))/k!)) and O((m+2^h +occ)log n))
The parameter δ, known as substring complexity, is a recently introduced measure of repetitiveness that serves as a unifying and lower-bounding metric for several popular measures, including the number of phrases in the LZ77 factorization (denoted by z) and the number of runs in the Burrows-Wheeler Transform (denoted by r). Moreover, O(δ log (n/δ)) represents the optimal space required to encode the data in terms of n and δ, helping us see how close our space is to the minimum required. In another trade-off, we match the query time of Cole et al.’s index using O(n+δ log (n/δ) ⋅ (clogδ)^{k+ε}/k!) space, where ε > 0 is an arbitrarily small constant. We also demonstrate how these techniques can be applied to a more general indexing problem, where the query pattern includes k-gaps (a gap can be interpreted as a contiguous sequence of wildcard characters)
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